1. Field of the Invention
The present invention relates to a polyester fiber the woven fabrics and knitted fabrics of which provide good drape and silhouette comparable to or better than rayon fabrics.
2. Description of the Prior Art
Polyester fiber has become a prominent synthetic fiber in garment use because of its favorable properties such as wash-and-wear, heat setting and easy care. These properties have improved because of improvement of raw materials and processing technology. Despite these advantages, fabrics made therefrom have heretofore suffered from a less than adequate feel and hand as compared to natural fibers. A variety of techniques have heretofore been proposed to overcome this disadvantage. Nevertheless, there are still many unsolved problems regarding the drape and silhouette of polyester woven and knitted fabrics.
Conventional means used to improve drapes in polyester woven and knitted fabrics are to lower the diameter of the fiber or to increase the alkali-soluble matter contained therein. According to these means, the flexibility and shear rigidity of polyester fiber are reduced and this leads to an improved drape. On the other hand, the reduction of rigidity makes the fabrics flexible to such an extent that these conventional means are of no practical use. These and other disadvantages of the prior art are overcome by the instant invention which in one of its more broader aspects comprises an improved polyester fiber, said improvement comprising (a) said fiber containing a density increasing amount of particles having a specific gravity higher than the polyester polymer from which the fiber is made and (b) a roughened surface thereby providing improved drape and silhouette to woven and knitted fabrics made therefrom.